Abstract
Orienting attention in time enables us to prepare for forthcoming perception and action (e.g. estimating the duration of a yellow traffic light when driving, approximating when to swing at a tennis ball). While temporal orienting can facilitate performance on simple tasks, its influence on complex tasks involving competing response choices is unclear. Here, we adapted the Flanker paradigm to a choice reaching task where participants used a computer mouse to reach to the left or right side of the screen as indicated by the central arrow presented with either the congruent or incongruent flankers. We assessed the effects of temporal orienting by manipulating goal-driven temporal expectation (based on probabilistic variations in target timing) and stimulus-driven temporal priming (based on sequential repetitions versus switches in target timing). We tested how temporal orienting influenced the dynamics of response conflict resolution. Recent choice reaching studies have indicated that under response conflict, delayed movement initiation captures the response threshold adjustment process, whereas increased curvature toward the incorrect response captures the degree of coactivation of the response alternatives during the controlled response selection process. Both temporal expectation and temporal priming reduced the initiation latency regardless of response conflict, suggesting that both lowered response thresholds independently of response conflict. Notably, temporal expectation, but not temporal priming, increased the curvature toward the incorrect response on incongruent trials. We further observed a complementary relationship between the response threshold adjustment and controlled response selection processes of response conflict resolution as shorter initiation latencies predicted greater curvature on incongruent trials, controlling for temporal orienting. These results suggest that temporal orienting generally increases motor preparedness, but the goal-driven mechanisms of temporal orienting particularly interferes with response conflict resolution, potentially through its strong influence on response thresholds. Overall, our study highlights the interplay between temporal orienting and cognitive control in goal-directed action.